Hydro Energy

Harnessing the force of falling water may be the world's oldest source of mechanical power. Hydro power currently supplies 10 percent of the nation's electricity and 80 percent of the electricity now produced from renewable resources.

Normally, rainwater and melting snow flows by gravity, producing streams, rivers, and lakes. Hydro power facilities intercept the water on its downward path, converting its mechanical energy into electricity. Because the cycle of water evaporating from the heat of the sun and falling back to earth is continuously renewed by the sun's energy, hydro power is often considered a renewable energy resource. However, the construction and operation of hydro power dams impact natural river systems and fish and wildlife. Whether specific hydro power projects create unacceptable environmental damage requires a case-by-case review.